Level attachment for chain saw



March 27, 1962 P. c. DOOLEY LEVEL ATTACHMENT FOR CHAIN SAW Filed Dec.29, 1958 INVENTOR. PHILIP C. DOOLEY FIG.3

BY BUCKHORN {\CHEATHAM & BLORE ATTORNEY! United 1 rates This inventionrelates to attachments for chain saws and particularly to attachmentspermitting the saw to cut off work at a predetermined place or level.

For convenience, the invention will be explained in connection withcutting off wooden piling, but the invention is obviously not intendedto be restricted to this use and has other uses.

After piling is driven into place, the piling must be cut off so thatthe top surfaces of the piles lie at a predetermined level. Heretofore,the most conventional way of accomplishing this has been to nailstringers to the piling at the predetermined level and use a hand saw tocut ofi a pile flush with the upper surfaces of the stringers. Thestringers thus act as guide members for the saw. Attempts have also beenmade to use chain saws, but this has not been satisfactory, becausethere is no way to guide the saw and thus the level of a pile top is atthe level at which the saw is held. Where attempts have been made to usestringers as a guide, this has proved ineffective since the chain sawmerely cuts into the stringers.

It is a main object of the present invention to provide an attachmentfor a chain saw permitting a piece of work to be cut off level with aguide member or guide members in a rapid and accurate manner.

A more specific object of the invention is to provide such an attachmentwhich is secured to the saw bar of a chain saw, and which requires onlyminor modification of the saw bar to effect the securement, and whichminor modifications may be made by the user.

A more particular object of the invention is to provide an attachment inthe form of a pair of spacer plate means securable to the saw bar of achain saw to engage spaced guide members to hold the cutter teeth of thesaw chain in position to cut off the work level or flush with the guidemembers.

Various other objects of the invention will be apparent from thefollowing description taken in connection with the accompanying drawingswherein:

FIG. 1 is a perspective view showing a chain saw equipped with anattachment of the present invention cutting off piling flush with a pairof stringers;

FIG. 2 is a view of the opposite side of the saw bar than shown in FIG.1, the view being taken on an enlarged scale and more clearly showingthe attachment of the subject invention; and

FIG. 3 is an enlarged, sectional View taken along line 33 of FIG. 1,showing the relationship of the chain saw and the work.

Referring to the drawings, there is a chain saw generally indicated bythe reference numeral 11, the chain saw being of conventionalconstruction with minor modifications to be referred to hereinafter. Thechain saw is shown cutting ofi the tops of piling including piles P1,P2, P3, P4, P5 and P6 level with the upper surfaces of stringers S1 andS2 nailed or otherwise secured to the pile at a desired level. The sawincludes a motor 13 mounted on a frame 14 and driving a chain 15 whichis guided by a saw bar 17. The inboard end or base end of the saw barconventionally is provided with a slot 19, as best shown in FIG. 2, toreceive a pair of bolts 21 to secure the bar to a flange or pad 22 whichis a part of or is secured to the frame 14 of the saw.

As is evident from FIG. 3, the bar 17 is thinner than the verticalthickness of the saw chain 15, as the parts are shown in FIG. 3, topermit the saw bar to freely pass into the kerf 23 cut by the saw chainin the work.

The attachment of the present invention includes a pair of plate means,the first including a main, flat, oblong, generally rectangular guideplate 31, which is shown in FIGS. 2 and 3, and a shim plate 33 ofsimilar shape shown in FIG. 3. The shim plate, however, is considerablythinner than the guide plate. The plate and its shim are secured to thebar 17 by a pair of bolts 35. These bolts pass through a pair ofmatching elongated slots 37 formed in the plate and shim and alsothrough a pair of holes 39 formed in the bar 17. The bar is notconventionally provided with these holes 39 and they therefore must bedrilled therein by the user. It is pointed out that the plate 31 and itsshim are located near the outboard end of the guide bar.

The bolts have fiat heads 41 slidably fitting Within countersunk portion4-3 of the slot 37 of the plate 31 so that the heads are flush with ordisposed in countersunk relation with respect to the bottom or exposedsurface of the plate 31. Wing nuts 45 are threaded on the protrudingends of the bolts 35 to hold the plate 3-1 and its shim firmly againstthe saw bar.

The combined thickness of plate 31 and its shim is equal to the distancethe saw chain projects downwardly beyond the lower face of the saw bar,as the parts are shown in FIG. 3. The plate 31 rests on the stringer S2as is apparent from FIGS. 1 and 3.

The slotted connection between the saw bar and the plate 31 and its shimprovides for longitudinal adjustment of the plate and its shim relativeto the saw bar for a purpose to be described hereinafter.

The other plate means comprises a smaller plate 51 and a shim 53 ofsimilar shape secured by a bolt 54 to the inboard end of the saw bar onthe underside thereof as the bar is shown in FIG. 2. The bolt passesthrough a hole formed in the saw bar, the hole being located so that astraight edge of the plate 51 and a similar edge of the shim 53 abutagainst a straight edge of the flange 22 to prevent the plate 51 and theshim 53 from turning relative to the saw bar. This would be undesirablesince the plate and shim would then come into engagement with the sawchain.

The combined thickness of the plate 51 and its shim is the same as thecombined thickness of the plate 31 and its shim. The plate 51 isdesigned to engage the stringer S1 closest to the motor housing tosupport the inboard end of the saw bar on the stringer with the sawchain teeth in position to cut off piling at the level of the uppersurfaces of the stringer.

To enable the attachment to be used with different sizes of piling orwork, the outboard plate and its shim may be shifted relative to the sawbar upon loosening of the nut 45. It is apparent from FIG. 2 that thebolts 35 are spaced apart a distance only a minor fraction of the lengthof the slots 37. Thus, while the two bolts prevent turning of theoutboard plate and its shim relative to the saw bar, they permitsubstantial adjustment of the outboard plate and its shim relative tothe saw bar to adjust the attachment for engagement with differentlyspaced guide means or stringers. Thus different size work may be readilyaccommodated.

With the attachment of the present invention, the piling can be cut offflush with the stringers because the two plate means serve as guides tosupport the saw chain in position to cut off the piling even with theupper surfaces of the stringers. The plate means also prevent the sawfrom digging into the work or stringers, because the plates will cause abinding action of the saw within its kerf if the saw bar is not heldparallel to the stringers or other guide members.

While the attachment is shown on a saw usedto cut oif piling, it isevident that a saw equipped with the attachment may be used for a widevariety ofpurposes in cutting ofr work level or flush with certain guidesurfaces or members.

It is pointed out that the attachment of the present invention can besecured to any chain saw by the pro-' vision of two holes for theoutboard plate means and a single bale for the inboard plate means. Itis further pointed out that the attachment may be readily removed fromthe saw bar to permit the saw bar to be used ina normal fashion. It isalso pointed out that the attachment of the present invention does notrequire dismantling or disassembly of the saw, and to the contrary theattachment may be secured to the saw without any disassembly beingrequired. In securing the plate 51 and its shim 53 in position, thebolts 21 are loosened an extent to allow the plate and its shim to beslipped into place and then the bolt 54 is inserted through theappropriate hole provided in the plate and the appropriate hole providedin the shim'. The bolts 21 and 54 are then tightened. After the sawchain has been sharpened a number of times, its width may decrease. Inorder to provide for flush cutting action with this decreasedwidth, thethickness of the shims 33 and 53 may be varied by substituting thinnershims for these. 7 a V The slot 19 in certain saw bars may extendforwardly sufiiciently to allow the bolt 54 to pass through the slotrather than providing a special hole for. the bolt. Having described theinvention in what is considered to be the preferred embodimentthereof,it is desired that it be understood that the invention is not to belimited other than by the provisions of the following claims.

Iclaim: 1. An attachmentfor a chain saw of the type having a motordriving a saw chain guided for movement by a one piece flat elongatedsaw bar said attachment comprising platemeans disposed against onesideof saidbar,

means for immovably securing said .plate means to said bar, said platemeans having a thickness such that the saw chain just clears the guidemeans of a workpiece, thus providing for'cutting ofi" work flush withguide means engaged by said plate means said plate mean's having'adimensionin the direction of the width of said-bar less than such widthand a dimension in the direction of the length of said bar less thansuch length to facilitate application of said plate means to said barwithout requiring removal of the saw chain from said blade.

2. An attachment as set forth in claim 1 in which there is a secondplate means secured to said saw bar on said one side in spaced relationto the first named plate means, said second plate means having athickness substantially the same as the first named plate meansfacilitating support of said saw bar on spaced guides that flank work tobe cut. 7 p

3. An attachment as set forth in claim 1 in which the plate meansincludes a guide plate and a separate shim disposed between the guideplate and the saw bar.

4. In combination with a chain saw of the type having a flat singlepiece elongated saw bar, a saw chain on said bar having teeth projectinglaterally of the bar so that the kerf cut by the teeth is substantiallygreater than the thickness of said bar, an attachment for said barcomprising plate means for slidably engaging a guide on Work to be cutand being disposed against one side of said bar, said plate means andbar having openings formed therethrough, means extending through saidopenings for securing said plate means to said bar, said plate meanshaving a thickness sufficient that when said plate means is in contactwith a guide or a workpiece, the teeth.

References Cited in the file of this patent UNITED STATES PATENTS1,221,401 Wilhelm et a1. Apr. 3. 1,861,162 Quist May 31, 1932 2,779,359Koski Jan. 29, 1957 FOREIGN PATENTS 740,965 Germany Nov. 1, 1943

